The proposal is an extension of a prospective longitudinal study of adolescents, and young adults (16 to 24 years) who had been diagnosed as hyperactive in childhood, between the ages of 6 and 12. Data have been collected on half the total cohort of 226 hyperactive youngsters. The new samples will include 111 probands, 45-50 normal siblings of probands, and 110 control adolescents who had no behavior problems in elementary school. Parents of probands and controls will also be evaluated. Assessments will be done blind to group membership. Extending the sample will provide the largest prospective study of an entire cohort of hyperactive children objectively evaluated at two time points. The project has 3 overall goals: 1) to contrast probands to their siblings and controls on a variety of outcome measures, e.g., DSM-III diagnoses, behavioral problems, academic and social adjustment, cognitive abilities, height, and weight; 2) to identify predictors of outcome among hyperactive children; 3) to compare the prevalence of DSM-III diagnoses in parents of probands with that in parents of controls in order to assess whether the syndrome of hyperactivity in children is associated with a specific pattern of psychiatric dysfunction in parents. This is a revised application of a previous proposal that was not funded. The following changes were made and are reflected in the present application: 1) Global Assessment Scales will be scored for each subject; 2) characteristics of early (childhood) treatment history will be included as predictors of adolescent outcome; 3) a large number of interviews will be rated for reliability purposes.